The purpose of an agitator in a washing machine is to mechanically agitate the articles to be washed in such a manner as to optimize the soil removing and other beneficial properties of washing aides such as detergent, bleach and fabric softener. At the same time agitation should not cause undue damage to the articles being washed and should use a minimum amount of energy. Also the agitator should not cause problems under adverse conditions such as low voltage, overloads, or too much detergent.
We have observed current pulsating washers, and found that the above advantages can be accomplished with a relatively slowly turning toroid of articles being washed. An agitator should submerge the articles quickly and provide a slowly turning toroid for washability. It must not tangle the articles nor be overly harsh on them. Moreover, an agitator must do this for a variety of article types and load sizes and under many operating conditions. We believe our agitator substantially meets these criteria.
Many prior art agitators have been designed for horizontal rather than pulsating agitation. Some have triangular shaped, generally rigid fins arranged vertically along an upstanding column to project radially therefrom. Others have radially directed vanes on the agitator column which flex as the agitator oscillates horizontally back and forth. Still others have flexible vanes projecting from a hollow perforate column so that the toroidal circulation produced by the agitator may include the hollow of the column.
The agitator of this invention, like the prior art agitators, is for a horizontally oscillating type clothes washer. However, our agitator has a hollow perforate column on a flared circular base or skirt and is configured to provide three distinct levels of agitator action. The first and second levels comprise four triangular fins vertically along a perforate column. The first or upper level which comprises about two-thirds of each fin including the apex thereof, helps submerge dry articles by pulling them downwardly, channelizes the articles between the fins to keep the articles in straight toroidal planes, and beats bellow-causing air out of the articles -- all without generating a "suds lock" condition.
The second or intermediate level comprises the lower one-third portion of each fin which is slightly tapered to provide just enough circulation to maintain the articles loose, unbunched, and channelized.
The third or bottom level comprises four rounded vanes projecting upwardly from the base or skirt with each vane having a decreasing cross section in the radially outer direction. The outer bottom edge of each vane is rooted to the base by a thin web, the decreasing cross section in combination with the thin web allowing the vane to flex in a controlled pattern when under load.
Accordingly, it is a general object of this invention to provide a horizontally oscillatable agitator configured upon oscillation thereof in a clothes and water-filled tub to produce a moving toroid of clothes that are loose, unbunched and channelized.
Another object is to provide an agitator adapted for horizontal oscillation which has a hollow perforate column on a flared circular skirt, triangular fins vertically affixed on the column and upstanding vanes flexibly affixed on the skirt, thereby combining upon oscillation thereof to produce three distinct levels of agitator action.
Another object is to provide an agitator like that in the last object wherein the vanes on the skirt have a blended decreasing cross section in the radially outer direction leading to a rounded terminus which is rooted to the skirt by a thin web, the decreasing cross section in combination with the thin web allowing the vane to flex in a controlled pattern when under load.